Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Except THX(R) Audio System

PINPOINT TEST B: POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS) - EXCEPT THX(R) AUDIO SYSTEM

Normal Operation
The audio control module (ACM) directs the audio signals to the speakers through separate positive and negative circuits for each of the 4 audio channels: LH front, RH front, LH rear, and RH rear. The ACM provides internal circuit protection for shorts to ground or shorts to voltage. For vehicles with door tweeter speakers, the speakers are wired in series with the door speakers.

- DTC B2965 (Audio System Speaker Circuit Fault) - sets when a short to ground is detected on any of the speaker circuits. For all audio systems except single CD, DTC B2965 also sets when an open circuit or short to voltage is detected.

For some audio systems, a short to ground or short to voltage in the circuitry to one of the speakers will cause all speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, DTC B2965 will set in the ACM, and this pinpoint test should be followed to isolate the damaged circuit.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- ACM

B1-B4:

B4-B6:

B6-B8: